Bill Ryan/The Gazette
A fallen tree, the result of damage from Friday night's thunderstorms, blocks the southbound lane of Route 355 near Clarksburg on Saturday.

Bill Ryan/The Gazette
Montgomery County Police direct traffic at Shady Grove Road and Route 355 in Gaithersburg on Saturday.Traffic lights were out throughout Montgomery County as the result of damage from Friday night's thunderstorms.

Bill Ryan/The Gazette
Montgomery County Police direct traffic at Shady Grove Road and Route 355 in Gaithersburg on Saturday.Traffic lights were out throughout Montgomery County as the result of damage from Friday night's thunderstorms.

Bill Ryan/The Gazette
Montgomery County Police direct traffic at Route 355 and Shady Grove Road in Gaithersburg after traffic signals went out following Friday night's thunderstorms.

Bill Ryan/The Gazette
Peter Sanchez and Ramundo Orellana of Gaithersburg, remove a fallen tree at a Gaithersburg home following Friday night's thunderstorms.

Sophie Yarborough/Special to The Gazette
A falling tree during Friday's storm damaged a house at the corner of Weymouth and Oxford in Garrett Park.

A wide line of fast-moving, ferocious thunderstorms that swept the region late Friday night left one dead in Montgomery County, left more than a million without power and forced mandatory restrictions on water use.

A 71-year-old Silver Spring woman is dead after a tree fell on her home Friday night, according to a statement from Montgomery County Police.

The victim's identity will be released following notification of family members. The woman lived alone. She was found Saturday morning by Fire and Rescue personnel who were responding to a call for a tree down on a home in the 10,000 block of Grant Avenue in Silver Spring.

Fire and Rescue personnel had to force entry into the home and discovered the woman's body in a second-floor bedroom. The apparent cause of death, according to the statement, is from a large maple tree falling through the roof onto her bed sometime Friday night.

Montgomery County Police and Fire and Rescue personnel ask neighbors to check at homes where there is major tree damage and call 911 to report any concerns to check the welfare of individuals at those homes

Multiple apartment buildings in the 5300 block of Riverdale Road in Riverdale Park were also damaged in the storm, including one that had lost a portion of its roof, said Mark Brady, spokesman for the Prince George's County's Fire and EMS service.

The damage had displaced an estimated 500 people living there, he said. Saturday afternoon, emergency services personnel were still determing the full number of people displaced and impacted by the storm, Brady said.

To care for the displaced residents, the county has established an emergency shelter at Northwestern High School at 7000 Adelphi Road in Hyattsville, Peterson said.

Restrictions and outages

The storms knocked out power at two water treatment plants, prompting a rare order from the Washington Suburban Sanitary Commission Saturday morning prohibiting car washing, lawn watering and other non-essential water uses.

The restrictions could last for “the next couple of days,” a WSSC spokesman said in a television interview. The utility, which serves Montgomery and Prince George's counties, is asking customers to limit toilet-flushing and dish- and clothes washing, and to “use water only as necessary.”

More than 422,000 Pepco customers are without power in a swath from the Frederick County line through southern Prince George's. A spokeswoman said it could take days for service to be restored and emergency crews cautioned people to stay away from downed lines.

BG&E listed more than 6,500 customers without power in Montgomery and more than 53,000 in Prince George's as of 2 p.m. PotomacEdison's website lists more than 6,900 Montgomery customers and more than 12,500 Frederick customers without power as of about 2 p.m.

WMATA spokeswoman Cathy Asato said Metro rail and bus service is running, but will be slow due to routes being blocked by debris.

Dealing with the aftermath

Prince George's County was struggling to deal with the aftermath of the severe thunderstorms. At midnight on June 30, the Prince George's County stood up its emergency operations center to deal with damage caused by the rolling thunderstorms. As of early afternoon on June 30, no fatalities had been blamed on the storm, said Scott Peterson, a county government spokesman.

Nearly all of the city of Bowie was cast into darkness by the June 29 storm. As of June 30, 80 percent of the city was still without power. Given the volume of outages across the area, it may take days for power to be fully restored to all residents, said Una Cooper a spokeswoman for the county in a statement.

The power loss also impacted traffic, as the majority of traffic lights across the city weren't working, said Cooper. Motorist should treat all intersections as four-way stops, Cooper said.

The storm appeared to have caused little damage to area homes, Cooper said.

“We seem to have come through it fairly well,” she said.

Saturday play in the third round of the PGA Tour's AT&T National at Congressional Country Club, a major golf tournament that attracts thousands to the Bethesda course, has been delayed and tour officials are assessing the course.

“Players were tweeting that trees and tents were down on the property, and cleanup was expected to take some time Saturday,” according to a PGA Tour update. “The third round was slated to begin at 7:10 a.m. in twosomes off the first tee, but that has been delayed at least three hours.”

Damage from the storm caused an inordinate number of calls in Montgomery County for downed transformers and trees falling on homes and electrical lines, said Graham. Cleanup crews are working to clear roads, but some bus service may be delayed.

Downed trees have played havoc at Mar-Lu Ridge, a church camp near Jefferson, said Sarah Lefler, executive director of the camp. A wedding was scheduled at the camp's chapel, which has a bucolic view of the Potomac River. The storm cut electricity and forced the festivities to the camp's other facilities that have power, Lefler said.

Among the damage was a large tree that fell over, damaging cars.

"Everybody's safe, no one got hurt, so that's the blessing," she said.

About 90 campers are expected Sunday for the start of a week at Mar-Lu Ridge. That will proceed as scheduled, she said. Parents should drop their children off at the camp's "Area 3" at 4340 Mountville Road. The building has power, she said.

More storms on the way

The storms arrived in the region about 10 p.m. after a day of record-breaking heat, racing through the area in less than an hour. Winds were measured at hurricane strength several reports of 80 mph winds were noted on weather websites and heavy rain bursts caused road flooding.

Tom Kines, a senior meteorologist with AccuWeather, said conditions yesterday were right for storms.

“Anytime you have temperatures near 100 and humidity like we had yesterday, that alone is sometimes enough to have pop-up thunderstorms,” Kines said.

At dawn's first light, the damage became more apparent, with tree limbs torn, power lines toppled and pieces of roofing scattered about neighborhoods.

Kines said that residents may be in for another round of thunderstorms, as heat and humidity continue and heat indexes eclipse 110 degrees.

“Another round of storms is likely,” Kines said. “Whether they're as bad as last night's remains to be seen. Obviously, one would hope they're not that bad. We'll probably see storms fire up across West Virginia in the afternoon and make it into [the D.C. area] during the evening hours.”

The National Weather Service has issued an excessive heat warning for a wide swath of Maryland including all of Prince George's County, as well as Charles, Anne Arundel, Calvert, Howard, Montgomery, St. Mary's counties. With temperatures expected to be sweltering, the NWS recommends area resident avoid strenuous activities, stay in air conditioned areas and drink plenty of water.